In many industrial applications, such as the manufacture of foods and beverages, hard surfaces commonly become contaminated with soils such as carbohydrate, proteinaceous, and hardness soils, food oil soils, fat soils, and other soils. Such soils can arise from the manufacture of both liquid and solid foodstuffs. Carbohydrate soils, such as cellulosics, monosaccharides, disaccharides, oligosaccharides, starches, gums and other complex materials, when dried, can form tough, hard to remove soils, particularly when combined with other soil components such as proteins, fats, oils, minerals, and others. The removal of such carbohydrate soils can be a significant problem. Similarly, other materials such as proteins, fats and oils can also form hard to remove soil and residues.
Food and beverage soils are particularly tenacious when they are heated during processing. Foods and beverages are heated for a variety of reasons during processing. For example, in dairy plants, dairy products are heated on a pasteurizer (e.g. HTST—high temperature short time pasteurizer or UHT—ultra high temperature pasteurizer) in order to pasteurize the dairy product. Also, many food and beverage products are concentrated or created as a result of evaporation.
Specific examples of food and beverage products that are concentrated using evaporators include dairy products such as whole and skimmed milk, condensed milk, whey and whey derivatives, buttermilk, proteins, lactose solutions, and lactic acid; protein solutions such as soya whey, nutrient yeast and fodder yeast, and whole egg; fruit juices such as orange and other citrus juices, apple juice and other pomaceous juices, red berry juice, coconut milk, and tropical fruit juices; vegetable juices such as tomato juice, beetroot juice, carrot juice, and grass juice; starch products such as glucose, dextrose, fructose, isomerose, maltose, starch syrup, and dextrine; sugars such as liquid sugar, white refined sugar, sweetwater, and inulin; extracts such as coffee and tea extracts, hop extract, malt extract, yeast extract, pectin, and meat and bone extracts; hydrolyzates such as whey hydrolyzate, soup seasonings, milk hydrolyzate, and protein hydrolyzate; beer such as de-alcoholized beer and wort; and baby food, egg whites, bean oils, and fermented liquors.
Clean-in-place cleaning techniques are a specific cleaning regimen adapted for removing soils from the internal components of tanks, lines, pumps and other process equipment used for processing typically liquid product streams such as beverages, milk, juices, etc. Clean-in-place cleaning involves passing cleaning solutions through the system without dismantling any system components. The minimum clean-in-place technique involves passing the cleaning solution through the equipment and then resuming normal processing. Any product contaminated by cleaner residue can be discarded. Often clean-in-place methods involve a first rinse, the application of the cleaning solutions, and a second rinse with potable water followed by resumed operations. The process can also include any other contacting step in which a rinse, acidic or basic functional fluid, solvent or other cleaning component such as hot water, cold water, etc. can be contacted with the equipment at any step during the process. Often the final potable water rinse is skipped in order to prevent contamination of the equipment with bacteria following the cleaning and/or sanitizing step.
Conventional clean-in-place techniques however are not always sufficient at removing all types of soils. Specifically, it has been found that low density organic soils, e.g., ketchup, barbeque sauce, are not easily removed using traditional CIP cleaning techniques. Thermally degraded soils are also particularly difficult to remove using conventional CIP techniques.
Brewery soils are another type of soil that is particularly difficult to remove from a surface. Brewing beer requires the fermentation of sugars derived from starch-based material e.g., malted barley. Fermentation uses yeast to turn the sugars in wort to alcohol and carbon dioxide. During fermentation, the wort becomes beer. Once the boiled wort is cooled and in a fermenter, yeast is propagated in the wort and it is left to ferment, which requires a week to months depending on the type of yeast and strength of the beer. In addition to producing alcohol, fine particulate matter suspended in the wort settles during fermentation. Once fermentation is complete, the yeast also settles, leaving the beer clear, but the fermentation tanks soiled.
Fermentation is sometimes carried out in two stages, primary and secondary. Once most of the alcohol has been produced during primary fermentation, the beer is transferred to a new vessel and allowed a period of secondary fermentation. Secondary fermentation is used when the beer requires long storage before packaging or greater clarity.
Often during the fermentation process in commercial brewing, the fermentation tanks develop a ring of soil, i.e., brandhefe ring, which is particularly difficult to remove. Traditional CIP methods of cleaning these tanks do not always remove this soil. Thus, brewers often resort to climbing inside of the tanks and manually scrubbing them to remove the soil.
What is needed therefore is an improved method for removing these types of soils that are not easily removed using conventional cleaning techniques. It is against this background that the present invention has been made.